Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint/openWorldHint/non-destructive, so the safety profile is covered. The description adds genuinely new behavior: pagination defaults and limits, the multi-state-view caveat ('check the state field in each item'), and the API key access requirement.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the resource and returned fields, then filters, pagination, and auth. Mostly earns its sentences, though the opening 'Recurly: Accounts with...' slightly overlaps with the following 'Lists Recurly accounts' clause.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully enumerates returned fields and the account_code handoff, plus pagination and auth requirements. It is essentially complete for a simple paginated list tool, missing only explicit guidance on cursor-based paging.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents state, cursor, and per_page. The description restates the state filter and per_page limits but does not add format or syntax detail (e.g. cursor semantics) beyond what the schema provides, so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Lists Recurly accounts') and enumerates the returned fields (code, name, email, company, state). The list-vs-get distinction from recurly_get_account is implicit rather than stated, so it is clear but not explicitly differentiated from siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear operational context: filter by state active/closed, 50-per-page default up to 200, and the note that the returned account_code feeds the other tools. It does not name alternatives (e.g. recurly_get_account) or exclusions, so it stops short of the when/when-not tier.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.